Coronavirus COVID-19 Vaccines

William M. Detmer, MD, supported by the Unbound Medicine Team

Updated: August 26, 2021

COVID-19 Vaccine Overview

  • Multiple vaccines have been developed against SARS-CoV-2, the virus causing COVID-19.
  • Several vaccines have been approved for emergency use in a number of countries (Table 1) and are now being distributed worldwide (Figure 1).
  • A total of 16 are under investigation in Phase 3 trials (Table 2), 64 are in clinical trials (Table 3), and 173 in preclinical evaluation.[1]
  • For details on variant strains of the SARS-CoV-2 virus and effects on vaccine efficacy, see Strains of SARS-CoV-2 causing COVID-19.
  • For overview of trial design, see Clinical Trial Phases and Definitions

Vaccine Administration

COVID-19 vaccine candidates studied in Phase 3 clinical trials began to be approved for emergency use in December 2020. The chart below shows the approximate number of doses that have been administered per 100,000 population to date in selected countries.

COVID-19 Vaccines Administered by Country
COVID-19 Vaccines Administered by Country
Cumulative COVID-19 vaccination doses administered per 100,000 people as of August 24, 2021.
Source: Our World in Data.[2]
Percent of US Population Receiving at Least One Vaccine Dose
Doses Administered in the United States
Graph shows the percentage of residents of the state or territory for the population 18 years and older who received at least one dose of vaccine. Non-residents who received vaccine are attributed to their state of residence as of August 24, 2021.
Source: US Centers for Disease Control

Vaccine News

RECENT UPDATES

  • BioNTech/Pfizer BNT162 vaccine
    • Large study from Israel published in NEJM showed low risk of adverse events – except for myocarditis, which occured 1 to 5 events per 100,000 persons (risk ratio compared to unvaccinated individuals: 3.24).[3] However, it was also found that the risk of myocarditis in persons infected with SARS-CoV-2 is much greater (risk ratio compared to uninfected individuals: 18.28). [August 25]
    • Vaccine fully approved by the U.S. FDA for individuals 16 years of age and older.[4] It remains under emergency use authorization (EUA) for individuals age 12–15 and for the administration of a third dose in certain immunocompromised individuals. [August 23]
    • Vaccine efficacy against Delta variant modestly lower than Alpha strain (88% vs 94%) after two doses according to study in the New England Journal of Medicine.[5] Efficacy difference in Delta vs Alpha strain was more pronounced after only one dose (36% vs 47%). [July 21]
    • Vaccine efficacy was 91% in fully vaccinated and 81% in partially vaccinated healthcare workers reported in New England Journal of Medicine.[6] Vaccinated individuals who developed COVID-19 had significantly lower viral load, shorter duration of virus detection, and less severe symptoms. [June 30]
    • Detailed safety and efficacy data in adolescents reported in New England Journal of Medicine.[7][May 27]
    • Vaccine receives Emergency Use Authorization for children 12–15 by U.S. FDA.[8] Although children and adolescents typically have milder Covid-19 symptoms than adults, more than 1.5 million U.S. cases have been reported in this age group. [May 10]
    • Approved for Emergency Use in the UK[9][December 2], Canada[10][December 9], United States[11][December 11], EU[12] [December 22], and other countries.
    • COVID-19 infection reduced by 95% in adult vaccine recipients according to Phase 3 trial results published in the New England Journal of Medicine.[13] In 43,548 participants, 170 confirmed cases of COVID-19 were evaluated, with 162 observed in the placebo group versus 8 in the vaccine group. Similar vaccine efficacy (generally 90 to 100%) was observed across subgroups defined by age, sex, race, ethnicity, baseline body-mass index, and the presence of coexisting conditions. Among 10 cases of severe Covid-19 with onset after the first dose, 9 occurred in placebo recipients and 1 in a BNT162b2 recipient. The safety profile of BNT162b2 was characterized by short-term, mild-to-moderate pain at the injection site, fatigue, and headache. The incidence of serious adverse events was low and was similar in the vaccine and placebo groups. [December 10]
    • More...
      • Vaccine 100% effective in preventing symptomatic Covid-19 in adolescents according to preliminary results of a Phase 3 trial in 2,260 adolescents 12 to 15 reported in a company press release.[14] The companies plan to submit these data to the FDA and EMA to expand emergency use of the vaccine in adolescents 12-15 years of age as quickly as possible. [March 31]
      • In correspondence to the editor published in NEJM the vaccine was found to be approximately two-thirds less effective at neutralizing the SARS-CoV-2 virus modified to have spike protein mutations similar to the B.1.351 (South Africa) variant.[15][February 17]
      • Results from a pre-print posted to bioRxiv indicate the vaccine is effective against the B.1.1.7 variant of SARS-CoV-2 first identified in the UK.[16][February 17]
      • Phase 3 study interim results reported in a company press release showed reduction of COVID-19 infection by 90% in vaccine recipients.[17] Results have not yet been published in a peer-reviewed journal. Study enrolled 43,538 participants to date and the first interim efficacy analysis was conducted when 94 COVID-19 cases were confirmed. The case split between vaccinated individuals and those who received the placebo indicated a vaccine efficacy rate above 90%, at 7 days after the second dose (given at day 28). No serious side effects were reported. The trial is continuing to enroll and is expected to continue through the final analysis when a total of 164 confirmed COVID-19 cases have accrued. [November 9]
      • Phase 1/2 trial published in Nature[18] showed that 60-person subset in immunized individuals generate a robust SARS-CoV-2-sepcific antibody and cellular mediated immune response which suggests multiple mechanisms with potential to protect against COVID-19. [September 30]
      • Phase 1/2 trial results published in Nature[19] showing that in 36 healthy adults 18–55 who received 2 doses of vaccine separated by 21 days developed RBD-binding and neutralizing antibodies higher than with natural infection. Mild to moderate side effects were common. [August 12; preprint published July 1]
      • U.S. government ordered 100 million doses of BNT162 for $1.95 billion as part of the U.S. Warp Speed program. A Phase 2b/3 safety and efficacy trial for the vaccine begins in late July 2020.[20][July 22]
  • University of Oxford / AstraZeneca AZD1222 vaccine
    • Vaccine efficacy against Delta variant modestly lower than Alpha strain (67% vs 74%) after two doses according to study in the New England Journal of Medicine.[5] Efficacy difference in Delta vs Alpha strain was more pronounced after only one dose (30% vs 49%). Overall efficacy of the AZD1222 vaccine was lower than the BNT162 vaccine. [July 21]
    • Rare side effect of thrombosis and thrombocytopenia found with this vaccine reported to be associated with detection of antibodies to platelet factor 4 (PF4).[21] Patients with post-vaccination thrombosis should therefore not be treated with platelet transfusion or heparin, which can worsen thrombosis. [April 16]
    • Company restated trial data and vaccine efficacy as 76%[22] after criticism from the Data and Safety Monitoring Board (DSMB) and U.S. National Institutes of Health (NIH) that the company may have included outdated information in its initial press release, overstating the vaccine efficacy.[23] Company reported more current data after the accrual of 190 cases of symptomatic Covid were seen in 32,449 trial participants. Results were overall similar to the original report. [March 24]
    • Vaccine 79% effective in preventing symptomatic Covid-19 according to preliminary results of a U.S. Phase 3 trial reported in a company press release.[24] Study enrolled 32,449 participants and the interim efficacy analysis was conducted when 141 COVID-19 cases were confirmed. Efficacy was comparable across ethnicity and age. Vaccine was well tolerated and no increased risk of thrombosis seen – specifically, no cases of cerebral venous sinus thrombosis (CVST) were reported. [March 22]
    • Vaccine is safe and not associated with increased overall risk of thromboembolic events concluded the European Medicines Agency (EMA). However, the vaccine may be associated with very rare cases of blood clots associated with thrombocytopenia, with or without bleeding, including rare cases of cerebral venous sinus thrombosis (CVST) and disseminated intravascular coagulation (DIC) - 25 cases in 20 million vaccinations. A causal link with the vaccine is not proven, but is possible and deserves further analysis.[25][March 18] Denmark, Iceland, Norway, Germany, France, Italy and several other countries had suspend the use of the vaccine pending this review. [March 11]
    • Vaccine not protective against mild-to-moderate Covid-19 due to the B.1.351 (South Africa) variant according to a study in the New England Journal of Medicine.[26][March 16] South Africa had already suspended use of the vaccine when preliminary data from this study was reported.[27][February 8]
    • Approved for Emergency Use in the UK[28][December 30], EU[29][January 29], Canada [February 26], and other countries.
    • COVID-19 infection reduced by 70% in vaccine recipients according to Phase 3 trial interim results reported in the Lancet.[30][December 8]
    • More...
      • Study published on a Lancet pre-print server[31] revealed vaccine efficacy of 67% overall with no hospitalizations in the vaccine group 22 days after the first dose. Efficacy appeared to be enhanced (82%) if the second dose was given 12 weeks or more after the first dose. The study also showed that transmission of the virus by vaccine recipients, as measured by weekly PCR tests, was reduced by 67% after a single dose and 50% after the two dose regimen. [February 2]
      • Phase 3 trial interim results reported in a company press release showed reduction of COVID-19 infection by 70% in vaccine recipients.[32] Based on these results, the company intends to submit for an Emergency Use Authorization (EUA) with the World Health Organization in coming weeks. [November 23]
      • Phase 3 trial resumed in the US after safety review by the FDA.[33][October 23]
      • Phase 3 trial resumed in the UK[34] (where the case of transverse myelitis occurred) but not yet in the United States, due to safety concerns at the NIH and FDA. [September 12]
      • Phase 3 trial paused[35] due to a trial participant developing a serious neurological event, thought to be transverse myelitis.[36]Transverse myelitis is a rare disorder of the spinal cord that, like Guillain-Barré syndrome, can be triggered by certain viral infections, including SARS-CoV-2 itself. Investigators and the U.S. National Institutes of Health have pledged to fully investigate whether this case could be associated with the vaccine. [September 9]
      • Preclinical study in rhesus macaques reported in Nature[37] showed that a single vaccination with ChAdOx1 nCoV-19 is effective in preventing damage to the lungs upon high dose challenge to both upper and lower respiratory tract with SARS-CoV-2; there was also no evidence of immune-enhanced disease in vaccinated animals. However, in regard to possible infectivity, nasal shedding of the virus was not significantly different between vaccinated and control animals. [July 30]
      • Phase 1/2 trial published in Lancet[38] showed that in adults age 18–55 a single dose elicited both humoral and cellular responses against SARS-CoV-2, with a booster immunization augmenting neutralizing antibody titres. No serious adverse effect were reported; mild-moderate side effects were common. [July 20]
      • Phase 3 trials that are underway in Brazil, South Africa, and the UK.
  • SinovacCoronaVac inactivated vaccine
    • COVID-19 infection reduced by 83% in adult vaccine recipients according to interim results of a Phase 3 trial published in the Lancet.[39] Vaccine was well tolerated. [July 8]
  • Novavax NVX-CoV2373 vaccine
    • Vaccine efficacy of 90% reported in Phase 3 trial published in the New England Journal of Medicine.[40]No serious infections occured in the vaccinated group. Side effects were generally mild and transient. [June 30]
    • Vaccine efficacy of 51% against S. Africa variant B.1.351 reported in Phase 2a-b trial in the New England Journal of Medicine.[41] Efficacy against the B.1.351 variant has previously been reported to be 64% with the J&J vaccine and 10% with the AstraZeneca vaccine. [May 5]
    • COVID-19 infection reduced by 96% for original strain and 86% for the B.1.1.7 (UK) variant strain in final Phase 3 trial results reported in a company press release.[42] The company expects the data to serve as the basis for submission for authorization to various regulatory agencies worldwide. [March 11]
    • In a separate study of 2,665 participants in South Africa, overall vaccine efficacy was 49% against predominantly the variant B.1.351 (South Africa) strain.[42][March 11]
    • More...
      • COVID-19 infection reduced by 89% in vaccine recipients according to Phase 3 trial interim results reported in a company press release.[43] Study enrolled ~15,000 participants and the first interim efficacy analysis was conducted when 62 COVID-19 cases were confirmed 7 days after a second vaccine dose. Preliminary analysis indicated that the UK variant strain that was increasingly prevalent was detected in over 50% of the PCR-confirmed symptomatic cases (32 UK variant, 24 non-variant, 6 unknown). Based on PCR performed on strains from 56 of the 62 cases, efficacy by strain was calculated to be 95.6% against the original COVID-19 strain and 85.6% against the UK variant strain. [January 28]
      • Phase 3 trial begins with 10k participants in the UK.[44] A similar trial is expected to start in the U.S in October. [September 24]
      • Phase 1/2 trial published in New England Journal of Medicine[45] showed that in 106 healthy adults age 18–59 who received two doses spaced 21 days apart had robust immune responses with both IgG and neutralization antibodies 4-fold higher than seen in natural infection. Mild-moderate side effects were common and greater local and systemic reactogenicity occurred with the second dose. [September 2]
      • Received U.S. Warp Speed funding for protein-based vaccine development and clinical trials.[46][July 7]
  • Johnson & Johnson/Janssen Ad26.COV2-S vaccine
    • Vaccine distribution resumed in U.S. following a thorough safety review, including two meetings of the CDC’s Advisory Committee on Immunization Practices.[47] To date 15 cases of thrombosis-thrombocytopenia syndrome (TTS) had been reported in the U.S., all cases occurring in women between the ages of 18 and 59, with a median age of 37 years, with onset 6–15 days after vaccination. Monitoring for safety will continue. [April 23]
    • COVID-19 infection reduced by 66% in vaccine recipients in Phase 3 ENSEMBLE trial published in the New England Journal of Medicine.[48][49] Study enrolled nearly 40,000 participants and the efficacy analysis was conducted when COVID-19 cases were confirmed 28 days after a single-dose vaccine. The onset of protection was observed as early as 14 days. Level of protection varied by geography likely due to different circulating SARS-CoV-2 strains: effectiveness was 72% in the US, 68% in Brazil, and 64% in South Africa. [April 21]
    • European Medicines Agency (EMA) concluded that a warning about unusual blood clots with low blood platelets should be added to the product information for this vaccine in the European Union, but that regulators in individual E.U. member states should decide how to proceed with vaccine authorization taking into account case loads and vaccine availability.[50][April 20]
    • Vaccine distribution paused by U.S. FDA and CDC while examining safety issues related to blood clotting.[51] Out of 6.8 million doses given in the U.S. to date, there have been 6 reported cases of cerebral venous sinus thrombosis (CVST) seen in combination with thrombocytopenia. All occurred in women between ages of 18 and 48, 6–13 days after vaccination. CDC’s Advisory Committee on Immunization Practices (ACIP) will meet to further review these cases and assess their potential significance. [April 13]
    • Approved for Emergency Use in the US.[52] United States FDA analysis showed vaccine had efficacy of 72% in the US, 64% in South Africa, and 61% in Latin America. [February 27]
    • COVID-19 infection reduced by 66% in vaccine recipients in Phase 3 trial interim results reported in a company press release.[49] Study enrolled nearly 44,000 participants and the first interim efficacy analysis was conducted when 468 COVID-19 cases were confirmed 28 days after a single-dose vaccine. The onset of protection was observed as early as 14 days. Level of protection varied by geography likely due to different circulating SARS-CoV-2 strains: effectiveness was 72% in the US, 66% in Latin America, and 57% in South Africa. [January 29]
    • More...
      • COVID-19 infection reduced by 66% in vaccine recipients in Phase 3 trial interim results reported in a company press release.[49] Study enrolled nearly 44,000 participants and the first interim efficacy analysis was conducted when 468 COVID-19 cases were confirmed 28 days after a single-dose vaccine. The onset of protection was observed as early as 14 days. Level of protection varied by geography likely due to different circulating SARS-CoV-2 strains: effectiveness was 72% in the US, 66% in Latin America, and 57% in South Africa. [January 29]
      • Trials resumed in the US after safety review by the company and an independent Data Safety Monitoring Board (DSMB) found no evidence that the vaccine candidate caused the medical event experienced by one study partipant.[53][October 23]
      • All trials of this vaccine paused (including Phase 3 trial)[54] due to an unexplained illness in a study participant. The company and a DSMB are investigating. [October 12]
      • Phase 3 trial (ENSEMBLE) begun with 60,000 participants from multiple country.[55][September 23]
      • Preclinical study in rhesus macaques reported in Nature[56] showed a single dose of the adenovirus serotype 26 (Ad26) vector-based vaccine induced robust neutralizing antibody responses and provided complete or near-complete protection in bronchoalveolar lavage and nasal swabs following SARS-CoV-2 challenge. [July 30]
      • Phase 1/2 trial began in late July.
      • The company received Warp Speed funding of $456 million for pre-clinical and Phase 1 clinical trials. [March 30]
  • Moderna mRNA-1273 vaccine
    • In vitro neutralization studies not yet published in a peer-reviewed journal show vaccine activity against emerging strains of SARS-CoV-2.[57],[16] Moderna vaccine produced neutralizing titers against emerging variants including B.1.1.7 (first identified in the UK) and B.1.351 (first identified in South Africa [SA]). The vaccine produced neutralizing antibodies against B.1.1.7 (UK) at levels comparable to prior variants but neutralization antibody induction was 6-fold lower in the B.1.351 (SA) variant. Despite this reduction, the company believes that neutralizing titer levels with B.1.351 are still high enough to be protective. However, they plan to produce a vaccine booster targeted at the SA variant and begin a Phase 1 study of that booster within the next several months. [January 25]
    • Approved for Emergency Use in the US[11][December 18], Canada[58][December 23], EU[59][January 6], and the UK[60][January 8].
    • COVID-19 infection reduced by 94% and severe COVID-19 reduced by 100% in vaccine recipients according to Phase 3 trial final results reported in the New England Journal of Medicine.[61] In 30,420 participants, 196 confirmed cases of COVID-19 were evaluated, with 185 observed in the placebo group versus 11 in the vaccine group. Efficacy was similar across key secondary analyses, including assessment 14 days after the first dose, analyses that included participants who had evidence of SARS-CoV-2 infection at baseline, and analyses in participants 65 years of age or older. Severe Covid-19 occurred in 30 participants, with one fatality; all 30 were in the placebo group. Moderate, transient reactogenicity after vaccination occurred more frequently in the mRNA-1273 group. Serious adverse events were rare, and the incidence was similar in the two groups. [December 30]
    • More...
      • Phase 3 study interim results reported in a company press release showed reduction of COVID-19 infection by 95% in vaccine recipients.[62] Results have not yet been published in a peer-reviewed journal. Study enrolled more than 30,000 participants to date and the first interim efficacy analysis was conducted when 95 COVID-19 cases were confirmed beginning two weeks after the second dose. Of these cases, 90 cases of COVID-19 were observed in the placebo group versus 5 in the vaccine group. Eleven severe cases were reported – all 11 cases occurred in the placebo group and none in the vaccine group. No serious side effects were reported. The trial is continuing to enroll and is expected to continue through the final analysis. [November 16]
      • Results of Phase 1 clinical trial in older adults (56+ years of age) published in the New England Journal of Medicine[63] showed a robust antibody and cellular immune response in vaccinated individuals. Mild-moderate side effects were common but self-limited. [September 29]
      • Preclinical study in non-human primates reported in New England Journal of Medicine.[64] Two injections elicited high levels of neutralizing antibody and Th1 CD4 T-cell responses in rhesus macaques. Two days after challenge of vaccinated animals with intranasal and intratracheal virus, viral replication was undetectable in bronchoalveolar-lavage fluid and nasal secretions. [July 28]
      • Phase 1 study published in NEJM.[65] Forty-five adults age 18–55 were tested with one of three dose levels given as 2 vaccinations 28 days apart. All subjects produced antibodies and neutralizing activity on par with natural infection. Mild-moderate side effects were common. [July 14]
  • Gamaleya Research Institute Gam-COVID-Vac vaccine
    • COVID-19 infection reduced by 92% in vaccine recipients according to Phase 3 trial interim results reported in the Lancet.[66] Study enrolled ~20,000 participants > age 18 in Moscow and the first interim efficacy analysis was conducted when 78 COVID-19 cases were confirmed 21 days after the first dose (the day of dose 2). Most reported adverse events were mild. 45 (0.3%) of 16,427 participants in the vaccine group and 23 (0.4%) of 5,435 participants in the placebo group had serious adverse events; none were considered associated with vaccination as confirmed by the independent data monitoring committee. [February 2]
    • More...
      • Phase 1/2 trial results published in Lancet[67] showed 76 adults receiving one of two vaccine types (rAd26-S or rAd5-S) either alone or with a booster at 21 days generated both neutralizing and specific IgG antibodies. Mild-moderate side effects (pain at injection site, fever, headache, myalgia) were common, but no major side effects were reported. [September 4]
      • Phase 1 trials of this vaccine were registered in June 2020 but no results have have been published in the scientific literature. Despite this, Russian President Vladimir Putin announced regulatory approval of the vaccine (to be called "Sputnik V" in foreign markets). Mass vaccination in Russia is expected to start in October 2020.[68][August 11]
  • INOVIO INO-4800 vaccine
    • Phase 2/3 has been put on partial clinical hold until questions posed by the U.S. FDA about the candidate and the delivery device (CELLECTRA® 2000) have been satisfactorily addressed. This hold is not due to the occurrence of any adverse events. [September 28]
    • Reports in a press release success of DNA-based vaccine INO-4800 in Phase 1 trial.[69][June 30]
  • Wuhan Institute of Biological Products / Sinopharm β-propiolactone-inactivated-whole-virus vaccine
    • Interim analysis of a Phase 1/2 trial reported in JAMA[70] showed that in 225 healthy adults aged 18–59 two injections of a medium dose spaced 21 days apart generated the most neutralizing and specific IgG antibodies and those levels were reported to be comparable to other vaccine candidates (but no direct comparisons was made to those vaccines or to convalescent plasma). Side effects were mild, self-limited and lower in frequency than what has been reported for other vaccine types. [August 13]
  • CanSino Biologics Adenovirus Type 5 vectored vaccine
    • Phase 2 trial published in Lancet[71] showed that in 382 adults age ≥ 18 a single dose induced cellular or humoral immune responses at day 28 post vaccination in 91–95% of recipients depending on the dose. Mild-moderate side effects were common; Grade 3 adverse effects were seen in 9%. [July 20]
    • Received Military Specially-needed Drug Approval (軍隊特需藥品批件) for non-replicating adenovirus vaccine Ad5-nCoV for use in the Chinese military.[72][June 25]

Vaccines Approved for Emergency Use

The table belows shows COVID-19 vaccines that have been approved for emergency use (green), have reported vaccine efficacy from a Phase 3 trial (blue), or are under investigation in a Phase 3 trial.

Table 1. COVID-19 Vaccines Approved for Emergency Use or in Phase 3 Trials

Developer

# in
Trial

Phase 3
Efficacy

Emergency
Approval

#

Spacing
(Days)

Vaccine
Type

Storage
Temp

Warp SpeedPfizer / BioNTech
BNT162b2, Tozinameran, Comirnaty

44k

95%[13]

UK: 2-Dec[9]
CA: 9-Dec[10]

US: 11-Dec[11]; Full approval: 23-Aug

EU: 22-Dec[12]

2

21

mRNA

-70ºC

Warp SpeedModerna
mRNA-1273

30k

94%[61]

US: 18-Dec[73]

CA: 23-Dec[58]

EU: 06-Jan[59]

UK: 08-Jan[60]

2

28

mRNA

2–8ºC

Warp SpeedJohnson & Johnson
Ad26.COV2.S, JNJ-78436735

44k

66%[48]

US: 27-Feb[52];
Paused 13-Apr[51]

Resumed 23-Apr[47]

CA: 05-Mar

EU: 11-Mar

1

-

Adenovirus

2–8ºC

Warp SpeedAstraZeneca / Oxford
AZD1222

24k

67%[30],[31]

UK: 30-Dec[28]

AR: 30-Dec

IN: 03-Jan

MX: 04-Jan

BR: 17-Jan

EU: 29-Jan[29]

CA: 26-Feb

2

28

Adenovirus

2–8ºC

Gamaleya Research Institute
Gam-COVID-Vac (Sputnik V)

20k

92%[66]

RU: 11-Aug[74]
MX: 03-Feb

2

21

Adenovirus

-18ºC

Sinovac
CoronaVac

26k

83%[39]

CN: 29-Dec

2

14

Inactivated

2–8ºC

Warp SpeedNovavax
NVX-CoV2373

30k

90%[40]

2

21

Protein Subunit

2–8ºC

Sinopharm
Inactivated virus, BBIBP-CorV

50k

72% (self report)

CN: 25-Feb

2

21

Inactivated

Bharat Biotech
BBV152

25k

Not yet reported

IN: 03-Jan

2

14

Inactivated

CanSino Biologics
Ad5-nCoV

40k

65% (self report)

CN: 25-Feb

1

-

Adenovirus

2–8ºC

CureVac AG
CVnCoV

2

28

Protein Subunit

Trial = # of Phase 3 trial participants; Phase 3 Efficacy = Vaccine Efficacy/Effectiveness (reduction in disease among the vaccinated group); Emergency Approval = Date of Emergency Use Authorization (EUA); # = Number of Doses Required; US = United States; UK = United Kingdom; CA = Canada; EU = European Union; AR = Argentina; IN = India; MX = Mexico; CN = China; BR = Brazil

Warp SpeedRecipient of U.S. Operation Warp Speed Funding

Table 2. COVID-19 Candidate Vaccines in Phase 3 Trials

Developer

Phase 1*

Phase II

Phase III

Pfizer / BioNTech/
BNT162

NCT04368728
Results in NEJM[75]

NCT04537949
Results in Nature[19]

NCT04537949
Positive final results.[17],[76]

Moderna/ NIAID
mRNA-1273

NCT04283461
Results in NEJM[65],[63]

NCT04405076

NCT04470427

Positive final results.[62],[77]

University of Oxford/ AstraZeneca
AZD1222

NCT04324606
Results in Lancet[78]

NCT04516746
Positive interim results.[32]

Sinovac
CoronaVac

NCT04383574
NCT04352608
Results in Science[79]

NCT04456595

Wuhan Institute of Biological Products/ Sinopharm
Inactivated virus

ChiCTR-2000031809
Results in JAMA[70]

ChiCTR-2000034780

Beijing Institute of Biological Products/ Sinopharm
BBIBP-CorV

ChiCTR-2000032459
Results in Lancet Infect Dis[80]

ChiCTR-2000034780

Bharat Biotech
BBV152

CTRI/2020/07/026300

CTRI-2020/11/028976

CanSino Biological Inc/ Beijing Institute of Biotechnology
Ad5-nCoV

NCT04313127
Results in Lancet[81]

NCT04341389
Results in Lancet[71]

NCT04526990; NCT04540419

Gamaleya Research Institute
Gam-COVID-Vac, Sputnik V

NCT04437875;
Results in Lancet[67]

NCT04587219

NCT04530396

Janssen Pharmaceutical Companies
Ad26.COV2.S

NCT04436276

NCT04505722

Novavax
NVX-CoV2373

NCT04368988
Results in NEJM[45]

2020-004123-16

*Trials spanning Phase 1 and 2 represent Phase 1/2 trials.

Vaccines in Clinical Trials

Table 3. COVID-19 Candidate Vaccines Undergoing Clinical Evaluation

Developer

Platform

Type

Current stage

Warp SpeedModerna/ NIAID

RNA

LNP-encapsulated mRNA (mRNA-1273)

Phase 3 NCT04470427; Positive final results.[62],[77]

Phase 2 NCT04405076

Phase 1 NCT04283461; Results in NEJM[65],[63]

Warp SpeedBioNTech/ Fosun Pharma/ Pfizer

RNA

3 LNP-mRNAs (BNT162)

Phase 3 NCT04368728; Positive final results.[17],[76]

Phase 1/2 NCT04537949; Results in Nature[19]

Warp SpeedUniversity of Oxford/ AstraZeneca

Non-Replicating Viral Vector

Weakened adenovirus (ChAdOx1-S; AZD1222)

Phase 3 NCT04516746; Positive interim results.[32]

Phase2b/3 NCT04400838

Phase 1/2 PACTR202006922165132; 2020-001072-15; Results in Lancet[81]

Sinovac

Inactivated

Inactivated + alum (CoronaVac; formerly PiCoVacc)

Phase 3 NCT04456595

Phase 1/2 NCT04383574 ; NCT04352608; Results in Science[79]

Wuhan Institute of Biological Products/ Sinopharm

Inactivated

Inactivated

Phase 3 ChiCTR2000034780

Phase 1/2 ChiCTR2000031809; Results in JAMA[70]

Beijing Institute of Biological Products/ Sinopharm

Inactivated

Inactivated (BBIBP-CorV)

Phase 3 ChiCTR2000034780

Phase 1/2 ChiCTR2000032459

CanSino Biological Inc./ Beijing Institute of Biotechnology

Non-Replicating Viral Vector

Adenovirus Type 5 Vector (Ad5-nCoV)

Phase 3 NCT04526990; NCT04540419

Phase 2 NCT04341389; Results in Lancet[71]

Phase 1 NCT04313127; Results in Lancet[81]

Gamaleya Research Institute

Non-Replicating Viral Vector

Adenovirus-based (Gam-COVID-Vac; Гам-КОВИД-Вак)

Phase 3 NCT04530396

Phase 1 NCT04436471; NCT04437875; Results in Lancet[67]

Anhui Zhifei Longcom Biopharmaceutical/ Institute of Microbiology, Chinese Academy of Sciences

Protein Subunit

Adjuvanted recombinant protein (RBD-Dimer)

Phase 2 NCT04466085

Phase 1 NCT04445194

Inovio Pharmaceuticals / International Vaccine Institute

DNA

DNA plasmid vaccine with electroporation (INO-4800)

Phase 1/2 NCT04336410; NCT04447781

Warp SpeedNovavax

Protein Subunit

Recombinant SARS CoV-2 glycoprotein nanoparticle vaccine adjuvanted with Matrix M (NVX-CoV2373)

Phase 3 2020-004123-16

Phase 2b NCT04533399

Phase 1/2 NCT04368988; Results in NEJM[45]

Warp SpeedJanssen Pharmaceutical Companies

Non-Replicating Viral Vector

Ad26.COV2.S

Phase 3 NCT04505722

Phase 1/2 NCT04436276

Bharat Biotech

Inactivated

Whole-Virion Inactivated

Phase 1/2 CTRI/2020/07/026300

Kentucky Bioprocessing, Inc

Protein Subunit

RBD-based

Phase 1/2 NCT04473690

Institute of Medical Biology, Chinese Academy of Medical Sciences

Inactivated

Inactivated

Phase 1/2 NCT04470609

Phase 1 NCT04412538

Warp SpeedSanofi Pasteur/GSK

Protein Subunit

S protein (baculovirus production

Phase 1/2 NCT04537208

Research Institute for Biological Safety Problems, Rep of Kazakhstan

Inactivated

Inactivated

Phase 1/2 NCT04530357

SpyBiotech/Serum Institute of India

VLP

RBD-HBsAg VLPs

Phase 1/2 ACTRN12620000817943

Genexine Consortium

DNA

DNA Vaccine (GX-19)

Phase 1 NCT04445389

Cadila Healthcare Limited

DNA

DNA plasmid vaccine

Phase 1/2 CTRI/2020/07/026352

Osaka University/ AnGes/ Takara Bio

DNA

DNA plasmid vaccine + Adjuvant

Phase 1 JapicCTI-205328

Gamaleya Research Institute

Non-Replicating Viral Vector

Adenovirus-based (Gam-COVID-Vac; Гам-КОВИД-Вак)

Phase 1 NCT04436471; NCT04437875

Clover Biopharmaceuticals Inc./ GSK/ Dynavax

Protein Subunit

Native like Trimeric subunit Spike Protein vaccine (SCB-2019)

Phase 1 NCT04437875

Arcturus/Duke-NUS

RNA

mRNA

Phase 1/2 NCT04480957

Vaxine Pty Ltd/ Medytox

Protein Subunit

Recombinant spike protein with Advax™ adjuvant

Phase 1 NCT04453852

University of Queensland/ CSL/ Seqirus

Protein Subunit

Molecular clamp stabilized Spike protein with MF59 adjuvant

Phase 1 ACTRN12620000674932p

Imperial College London

RNA

LNP-nCoVsaRNA

Phase 1 ISRCTN17072692

Curevac

RNA

mRNA

Phase 1 NCT04449276

Medigen Vaccine Biologics Corporation/ NIAID/ Dynavax

Protein Subunit

S-2P protein + CpG 1018

Phase 1 NCT04487210

People’s Liberation Army (PLA) Academy of Military Sciences/Walvax Biotech

RNA

mRNA

Phase 1 ChiCTR2000034112

Medicago Inc./ Université Laval

VLP

Plant-derived VLP

Phase 1 NCT04450004

Institute Pasteur/ Themis/ Univ. of Pittsburg CVR/ Merck Sharp & Dohme

Replicating Viral Vector

Measles-vector based

Phase 1 NCT04497298

ReiThera/ LEUKOCARE/ Univercells

Non-Replicating Viral Vector

Replication defective Simian Adenovirus (GRAd) encoding S

Phase 1 NCT04528641

Instituto Finlay de Vacunas, Cuba

Protein Subunit

RBD + Adjuvant

Phase 1 IFV/COR/04

FBRI SRC VB VECTOR, Rospotrebnadzor, Koltsovo

Protein Subunit

Peptide

Phase 1 NCT04527575

West China Hospital, Sichuan University

Protein Subunit

RBD (baculovirus production expressed in Sf9 cells)

Phase 1 ChiCTR2000037518

University Hospital Tuebingen

Protein Subunit

SARS-CoV-2 HLA-DR peptides

Phase 1 NCT04546841

COVAXX

Protein Subunit

S1-RBD-protein

Phase 1 NCT04497298

Beijing Wantai Biological Pharmacy/ Xiamen University

Replicating Viral Vector

Intranasal flu-based-RBD

Phase 1 ChiCTR2000037782

Vaxart

Non-Replicating Viral Vector

Ad5 adjuvanted Oral Vaccine platform

Phase 1 NCT04563702

Ludwig-Maximilians - University of Munich

Non-Replicating Viral Vector

MVA-SARS-2-S

Phase 1 NCT04569383

Adapted from Draft landscape of COVID-19 candidate vaccines. WHO. 22 December 2020.[1]

LNP = lipid nanoparticle; RBD = receptor-binding domain; mRNA = messenger RNA; VLP = virus-like particles

Warp SpeedRecipient of U.S. Operation Warp Speed Funding[82],[83]

Vaccine Trial Phases and Definitions

Preclinical Testing

In a Preclinical trial, the vaccine is given to animals such as mice or monkeys, typically rhesus macaques (Macaca mulatta), to see if it produces an immune response.

Phase 1

In a Phase I trial, the vaccine candidate is given to a small number of people to test safety and dosage as well as to confirm that it stimulates the immune system.

Phase 2

In a Phase II trial, the vaccine candidate is given to hundreds of people split into different age or risk groups groups to see if the vaccine acts differently in different populations. These trials further test the vaccine’s safety and ability to stimulate the immune system.

Phase 3

In a Phase III trial, the vaccine candidate is given to thousands of people and wait to see how many become infected, compared with those who received a placebo. These trials can determine if the vaccine protects against the coronavirus.

Approval

Regulators in each country review the trial results and decide whether to approve the vaccine or not. During a public health emergency, a vaccine may receive Emergency Use Authorization (EUA) before getting formal approval.

Phase 4

In a Phase IV trial – also known as a postmarketing surveillance trial or a confirmatory trial – the vaccine is monitored for safety, side effects and efficacy after it has been approved and made available to the public.

Warp Speed

The U.S. government’s Operation Warp Speed program is expected to name five or more vaccine projects to receive billions of dollars in federal funding before there’s proof that the vaccines work.

Combined Phases

Some coronavirus vaccines are now in combined phase trials to speed evalutation. For instance, many Phase 1/2 trials are underway to test a vaccine for the first time on hundreds of people.

COVID-19 ClinicalTrials.gov Trials

Feedback

We’d appreciate your feedback!

Share this page

Share by emailShare by FacebookShare by Twitter

Keywords

ncov vaccine updates, covid vaccine phase 4, covid-19 vaccine comparison table, covid vaccine comparison chart, covid-19 vaccine latest update, azd1222 covid vaccine, covid vaccine phases explained, covid 19 vaccines efficacy rate table

References

  1. COVID-19 vaccine tracker and landscape. World Health Organization. [https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candid...]
  2. Cumulative COVID-19 vaccination doses administered per 100 people. Our World in Data. [https://ourworldindata.org/covid-vaccinations]
  3. Barda N, Dagan N, Ben-Shlomo Y, et al. Safety of the BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Setting. N Engl J Med. 2021.  [PMID:34432976]
  4. FDA Approves First COVID-19 Vaccine: Approval Signifies Key Achievement for Public Health. FDA News. August 23, 2021. [https://www.fda.gov/news-events/press-announcements/fda-approves-first-cov...]
  5. Lopez Bernal J, Andrews N, Gower C, et al. Effectiveness of Covid-19 Vaccines against the B.1.617.2 (Delta) Variant. N Engl J Med. 2021;385(7):585-594.  [PMID:34289274]
  6. Thompson MG, Burgess JL, Naleway AL, et al. Prevention and Attenuation of Covid-19 with the BNT162b2 and mRNA-1273 Vaccines. N Engl J Med. 2021.  [PMID:34192428]
  7. Frenck RW, Klein NP, Kitchin N, et al. Safety, Immunogenicity, and Efficacy of the BNT162b2 Covid-19 Vaccine in Adolescents. N Engl J Med. 2021.  [PMID:34043894]
  8. Coronavirus (COVID-19) Update: FDA Authorizes Pfizer-BioNTech COVID-19 Vaccine for Emergency Use in Adolescents in Another Important Action in Fight Against Pandemic. FDA News Release. May 10, 2021. [https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-u...]
  9. UK medicines regulator gives approval for first UK COVID-19 vaccine. UK Medicines and Healthcare products Regulatory Agency (MHRA). December 2, 2020. [https://www.gov.uk/government/news/uk-medicines-regulator-gives-approval-f...]
  10. Regulatory Decision Summary - Pfizer-BioNTech COVID-19 Vaccine. Health Canada. December 9, 2020. [https://covid-vaccine.canada.ca/info/regulatory-decision-summary-detailTwo.html?linkID=RDS00730]
  11. FDA Takes Key Action in Fight Against COVID-19 By Issuing Emergency Use Authorization for First COVID-19 Vaccine. United States Food & Drug Administration (FDA) Press Release. December 11, 2020. [https://www.fda.gov/news-events/press-announcements/fda-takes-key-action-f...]
  12. EMA recommends first COVID-19 vaccine for authorisation in the EU. European Medicines Agency Press Release. December 22, 2020. [https://www.ema.europa.eu/en/news/ema-recommends-first-covid-19-vaccine-au...]
  13. Polack FP, Thomas SJ, Kitchin N, et al. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. N Engl J Med. 2020.  [PMID:33301246]
  14. Pfizer-BioNTech Announce Positive Topline Results of Pivotal COVID-19 Vaccine Study in Adolescents. Pfizer press release. March 31, 2021. [https://www.pfizer.com/news/press-release/press-release-detail/pfizer-bion...]
  15. Liu Y, Liu J, Xia H, et al. Neutralizing Activity of BNT162b2-Elicited Serum - Preliminary Report. N Engl J Med. 2021.  [PMID:33596352]
  16. Wu K, Werner AP, Moliva JI et al. mRNA-1273 vaccine induces neutralizing antibodies against spike mutants from global SARS-CoV-2 variants. bioRxiv January 25, 2021. [http://biorxiv.org/content/early/2021/01/25/2021.01.25.427948.full]
  17. Pfizer and Biontech Announce Vaccine Candidate Against Covid-19 Achieved Success in First Interim Analysis from Phase 3 Study. Pfizer Press Release. November 9, 2020. [https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-...]
  18. Sahin U, Muik A, Derhovanessian E, et al. COVID-19 vaccine BNT162b1 elicits human antibody and TH1 T-cell responses. Nature. 2020.  [PMID:32998157]
  19. Mulligan MJ, Lyke KE, Kitchin N, et al. Phase 1/2 study of COVID-19 RNA vaccine BNT162b1 in adults. Nature. 2020.  [PMID:32785213]
  20. Pfizer and BioNTech Announce an Agreement with U.S. Government for up to 600 Million Doses of mRNA-based Vaccine Candidate Against SARS-CoV-2. Businesswire. July 22, 2020. [https://www.businesswire.com/news/home/20200722005438/en/]
  21. Scully M, Singh D, Lown R, et al. Pathologic Antibodies to Platelet Factor 4 after ChAdOx1 nCoV-19 Vaccination. N Engl J Med. 2021.  [PMID:33861525]
  22. AZD1222 US Phase III primary analysis confirms safety and efficacy. AstraZeneca Press Release. March 25, 2021. [https://www.astrazeneca.com/media-centre/press-releases/2021/azd1222-us-ph...]
  23. NIAID Statement on AstraZeneca Vaccine. U.S. National Institutes of Health News. March 23, 2021. [https://www.nih.gov/news-events/news-releases/niaid-statement-astrazeneca-vaccine]
  24. AZD1222 US Phase III trial met primary efficacy endpoint in preventing COVID-19 at interim analysis. AstraZeneca press release. March 22, 2021. [https://www.astrazeneca.com/media-centre/press-releases/2021/astrazeneca-u...]
  25. COVID-19 Vaccine AstraZeneca: benefits still outweigh the risks despite possible link to rare blood clots with low blood platelets. European Medicines Agency News. March 18, 2021. [https://www.ema.europa.eu/en/news/covid-19-vaccine-astrazeneca-benefits-st...]
  26. Madhi SA, Baillie V, Cutland CL, et al. Efficacy of the ChAdOx1 nCoV-19 Covid-19 Vaccine against the B.1.351 Variant. N Engl J Med. 2021.  [PMID:33725432]
  27. South Africa suspends use of AstraZeneca’s COVID-19 vaccine after it fails to clearly stop virus variant. Science News. February 8, 2021. [https://www.sciencemag.org/news/2021/02/south-africa-suspends-use-astrazen...]
  28. Oxford University/AstraZeneca COVID-19 vaccine approved. UK Medicines and Healthcare products Regulatory Agency. December 30, 2020. [https://www.gov.uk/government/news/uk-medicines-regulator-gives-approval-for-first-uk-covid-19-vaccine]
  29. EMA recommends COVID-19 Vaccine AstraZeneca for authorisation in the EU. European Medicines Agency. January 29, 2021. [https://www.ema.europa.eu/en/news/ema-recommends-covid-19-vaccine-astrazen...]
  30. Voysey M, Clemens SAC, Madhi SA, et al. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet. 2020.  [PMID:33306989]
  31. Voysey M, Clemens SAC, Madhi SA, et al. Single Dose Administration and the Influence of the Timing of the Booster Dose on Immunogenicity and Efficacy Of ChAdOx1 nCoV-19 (AZD1222) Vaccine. [https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3777268]
  32. AZD1222 vaccine met primary efficacy endpoint in preventing COVID-19. AstraZeneca Press Release. November 23, 2020. [https://www.astrazeneca.com/media-centre/press-releases/2020/azd1222hlr.ht...]
  33. Global clinical trials of COVID-19 vaccine resume. Oxford Press Release. October 23, 2020. [https://www.ox.ac.uk/news/2020-10-23-global-clinical-trials-covid-19-vacci...]
  34. COVID-19 vaccine AZD1222 clinical trials resumed in the UK. AstraZeneca Press Release. September 12, 2020. [https://www.astrazeneca.com/media-centre/press-releases/2020/covid-19-vacc...]
  35. Statement on AstraZeneca Oxford SARS-CoV-2 vaccine, AZD1222, COVID-19 vaccine trials temporary pause. AstraZeneca [Press Release]. September 9, 2020. [https://www.astrazeneca.com/media-centre/press-releases/2020/statement-on-...]
  36. AstraZeneca Pauses Vaccine Trial for Safety Review. New York Times. September 8, 2020 [updated September 10, 2020] [https://www.nytimes.com/2020/09/08/health/coronavirus-astrazeneca-vaccine-...]
  37. van Doremalen N, Lambe T, Spencer A, et al. ChAdOx1 nCoV-19 vaccine prevents SARS-CoV-2 pneumonia in rhesus macaques. Nature. 2020.  [PMID:32731258]
  38. Folegatti PM, Ewer KJ, Aley PK, et al. Safety and immunogenicity of the ChAdOx1 nCoV-19 vaccine against SARS-CoV-2: a preliminary report of a phase 1/2, single-blind, randomised controlled trial. Lancet. 2020.  [PMID:32702298]
  39. Tanriover MD, Doğanay HL, Akova M, et al. Efficacy and safety of an inactivated whole-virion SARS-CoV-2 vaccine (CoronaVac): interim results of a double-blind, randomised, placebo-controlled, phase 3 trial in Turkey. Lancet. 2021;398(10296):213-222.  [PMID:34246358]
  40. Heath PT, Galiza EP, Baxter DN, et al. Safety and Efficacy of NVX-CoV2373 Covid-19 Vaccine. N Engl J Med. 2021.  [PMID:34192426]
  41. Shinde V, Bhikha S, Hoosain Z, et al. Efficacy of NVX-CoV2373 Covid-19 Vaccine against the B.1.351 Variant. N Engl J Med. 2021.  [PMID:33951374]
  42. Novavax Confirms High Levels of Efficacy Against Original and Variant COVID-19 Strains in United Kingdom and South Africa Trials. Company Press Release. March 11, 2021. [https://ir.novavax.com/news-releases/news-release-details/novavax-confirms...]
  43. Novavax COVID-19 Vaccine Demonstrates 89.3% Efficacy in UK Phase 3 Trial. Novavax Press Release. January 28, 2021. [https://ir.novavax.com/news-releases/news-release-details/novavax-covid-19...]
  44. Novavax Initiates Phase 3 Efficacy Trial of COVID-19 Vaccine in the United Kingdom. Novavax Press Release. September 24, 2020. [https://ir.novavax.com/news-releases/news-release-details/novavax-initiate...]
  45. Keech C, Albert G, Cho I, et al. Phase 1-2 Trial of a SARS-CoV-2 Recombinant Spike Protein Nanoparticle Vaccine. N Engl J Med. 2020.  [PMID:32877576]
  46. U.S. Will Pay $1.6 Billion to Novavax for Coronavirus Vaccine. New York Times. July 7, 2020. [https://www.nytimes.com/2020/07/07/health/novavax-coronavirus-vaccine-warp...]
  47. FDA and CDC Lift Recommended Pause on Johnson & Johnson (Janssen) COVID-19 Vaccine Use Following Thorough Safety Review. FDA News Release. April 23, 2021. [https://www.fda.gov/news-events/press-announcements/fda-and-cdc-lift-recom...]
  48. Sadoff J, Gray G, Vandebosch A, et al. Safety and Efficacy of Single-Dose Ad26.COV2.S Vaccine against Covid-19. N Engl J Med. 2021.  [PMID:33882225]
  49. Johnson & Johnson Announces Single-Shot Janssen COVID-19 Vaccine Candidate Met Primary Endpoints in Interim Analysis of its Phase 3 ENSEMBLE Trial. J&J Press Release. January 29, 2021. [https://www.jnj.com/johnson-johnson-announces-single-shot-janssen-covid-19...]
  50. COVID-19 Vaccine Janssen: EMA finds possible link to very rare cases of unusual blood clots with low blood platelets. European Medicines Agency News. April 20, 2021. [https://www.ema.europa.eu/en/news/covid-19-vaccine-janssen-ema-finds-possi...]
  51. Joint CDC and FDA Statement on Johnson & Johnson COVID-19 Vaccine. CDC News. April 13, 2021. [https://www.cdc.gov/media/releases/2021/s0413-JJ-vaccine.html]
  52. FDA Issues Emergency Use Authorization for Third COVID-19 Vaccine. FDA News Release. February 27, 2021. [https://www.fda.gov/news-events/press-announcements/fda-issues-emergency-u...]
  53. Johnson & Johnson Prepares to Resume Phase 3 ENSEMBLE Trial of its Janssen COVID-19 Vaccine Candidate in the U.S. Press Release. October 23, 2020. [https://www.jnj.com/our-company/johnson-johnson-prepares-to-resume-phase-3...]
  54. Johnson & Johnson Temporarily Pauses All Dosing in Our Janssen COVID-19 Vaccine Candidate Clinical Trials. Press Release. October 12, 2020. [https://www.jnj.com/our-company/johnson-johnson-temporarily-pauses-all-dos...]
  55. Johnson & Johnson Initiates Pivotal Global Phase 3 Clinical Trial of Janssen’s COVID-19 Vaccine Candidate. Press Release. September 23, 2020. [https://www.jnj.com/johnson-johnson-initiates-pivotal-global-phase-3-clini...]
  56. Mercado NB, Zahn R, Wegmann F, et al. Single-shot Ad26 vaccine protects against SARS-CoV-2 in rhesus macaques. Nature. 2020.  [PMID:32731257]
  57. Moderna COVID-19 Vaccine Retains Neutralizing Activity Against Emerging Variants First Identified in the U.K. and the Republic of South Africa. Moderna Press Release. January 25, 2021. [https://investors.modernatx.com/news-releases/news-release-details/moderna...]
  58. Regulatory Decision Summary - Moderna COVID-19 Vaccine. Health Canada. December 23, 2020. [https://covid-vaccine.canada.ca/info/regulatory-decision-summary-detailTwo.html...]
  59. EMA recommends COVID-19 Vaccine Moderna for authorisation in the EU. European Medicines Agency. January 6, 2021. [https://www.ema.europa.eu/en/news/ema-recommends-covid-19-vaccine-moderna-...]
  60. Moderna vaccine becomes third COVID-19 vaccine approved by UK regulator. Medicines and Healthcare products Regulatory Agency. January 8, 2021. [https://www.gov.uk/government/news/moderna-vaccine-becomes-third-covid-19-...]
  61. Baden LR, El Sahly HM, Essink B, et al. Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine. N Engl J Med. 2020.  [PMID:33378609]
  62. Moderna’s COVID-19 Vaccine Candidate Meets its Primary Efficacy Endpoint in the First Interim Analysis of the Phase 3 COVE Study. Company press release. November 16, 2020. [https://investors.modernatx.com/news-releases/news-release-details/moderna...]
  63. Anderson EJ, Rouphael NG, Widge AT, et al. Safety and Immunogenicity of SARS-CoV-2 mRNA-1273 Vaccine in Older Adults. N Engl J Med. 2020.  [PMID:32991794]
  64. Corbett KS, Flynn B, Foulds KE, et al. Evaluation of the mRNA-1273 Vaccine against SARS-CoV-2 in Nonhuman Primates. N Engl J Med. 2020.  [PMID:32722908]
  65. Jackson LA, Anderson EJ, Rouphael NG, et al. An mRNA Vaccine against SARS-CoV-2 - Preliminary Report. N Engl J Med. 2020.  [PMID:32663912]
  66. Logunov GY, Dolzhikova IV, Shcheblyakov DV, et al. Safety and efficacy of an rAd26 and rAd5 vector-based heterologous prime-boost COVID-19 vaccine: an interim analysis of a randomised controlled phase 3 trial in Russia. Lancet. Published online Februrary 2, 2021. [https://doi.org/10.1016/S0140-6736(21)00234-8]
  67. Logunov DY et al. Safety and immunogenicity of an rAd26 and rAd5 vector-based heterologous prime-boost COVID-19 vaccine in two formulations: two open, non-randomised phase 1/2 studies from Russia. Lancet. 396(10252), 649, e22-e24. DOI: [https://doi.org/10.1016/S0140-6736(20)31866-3]
  68. Russia Approves Coronavirus Vaccine Before Completing Tests. New York Times. August 11, 2020. [https://www.nytimes.com/2020/08/11/world/europe/russia-coronavirus-vaccine...]
  69. INOVIO Announces Positive Interim Phase 1 Data For INO-4800 Vaccine for COVID-19. Press Release. June 30, 2020. http://ir.inovio.com/news-releases/news-releases-details/2020/INOVIO-Annou...
  70. Xia S, Duan K, Zhang Y, et al. Effect of an Inactivated Vaccine Against SARS-CoV-2 on Safety and Immunogenicity Outcomes: Interim Analysis of 2 Randomized Clinical Trials. JAMA. 2020.  [PMID:32789505]
  71. Zhu FC, Guan XH, Li YH, et al. Immunogenicity and safety of a recombinant adenovirus type-5-vectored COVID-19 vaccine in healthy adults aged 18 years or older: a randomised, double-blind, placebo-controlled, phase 2 trial. Lancet. 2020.  [PMID:32702299]
  72. Recombinant Novel Coronavirus Vaccine (Adenovirus Type 5 Vector) Received Military Specially-needed Drug Approval. Hong Kong Stock Exchange Filing. June 25, 2020. https://www1.hkexnews.hk/listedco/listconews/sehk/2020/0629/2020062900123....
  73. FDA Takes Additional Action in Fight Against COVID-19 By Issuing Emergency Use Authorization for Second COVID-19 Vaccine. U.S. Food & Drug Administration Press Release. December 18, 2020. [https://www.fda.gov/news-events/press-announcements/fda-takes-additional-a...]
  74. Russia’s approval of a COVID-19 vaccine. Science. August 11, 2020. [https://www.sciencemag.org/news/2020/08/russia-s-approval-covid-19-vaccine...]
  75. Walsh EE, Frenck RW, Falsey AR, et al. Safety and Immunogenicity of Two RNA-Based Covid-19 Vaccine Candidates. N Engl J Med. 2020.  [PMID:33053279]
  76. Pfizer and BioNTech Conclude Phase 3 Study of COVID-19 Vaccine Candidate, Meeting All Primary Efficacy Endpoints. Pfizer Press Release. November 18, 2020. [https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-...]
  77. Moderna Announces Primary Efficacy Analysis in Phase 3 COVE Study for Its COVID-19 Vaccine Candidate and Filing Today with U.S. FDA for Emergency Use Authorization. Moderna Press Release. November 30, 2020. [https://investors.modernatx.com/news-releases/news-release-details/moderna...]
  78. Logunov DY, Dolzhikova IV, Zubkova OV, et al. Safety and immunogenicity of an rAd26 and rAd5 vector-based heterologous prime-boost COVID-19 vaccine in two formulations: two open, non-randomised phase 1/2 studies from Russia. Lancet. 2020.  [PMID:32896291]
  79. Gao Q, Bao L, Mao H, et al. Rapid development of an inactivated vaccine candidate for SARS-CoV-2. Science. 2020.  [PMID:32376603]
  80. Xia S, Zhang Y, Wang Y, et al. Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBIBP-CorV: a randomised, double-blind, placebo-controlled, phase 1/2 trial. Lancet Infect Dis. 2020.  [PMID:33069281]
  81. Zhu FC, Li YH, Guan XH, et al. Safety, tolerability, and immunogenicity of a recombinant adenovirus type-5 vectored COVID-19 vaccine: a dose-escalation, open-label, non-randomised, first-in-human trial. Lancet. 2020;395(10240):1845-1854.  [PMID:32450106]
  82. Fact sheet: explaining Operation Warp Speed. US Department of Health & Human Services. Published June 16, 2020. Accessed July 9, 2020. [https://www.hhs.gov/about/news/2020/06/16/fact-sheet-explaining-operation-warp-speed.html]
  83. O'Callaghan KP, Blatz AM, Offit PA. Developing a SARS-CoV-2 Vaccine at Warp Speed. JAMA. 2020.  [PMID:32628244]
  84. Deming ME, Michael NL, Robb M, et al. Accelerating Development of SARS-CoV-2 Vaccines - The Role for Controlled Human Infection Models. N Engl J Med. 2020.  [PMID:32610006]
  85. Graham BS. Rapid COVID-19 vaccine development. Science. 2020;368(6494):945-946.  [PMID:32385100]
  86. Keech C, Albert G, et al. First-in-Human Trial of a SARS CoV 2 Recombinant Spike Protein Nanoparticle Vaccine. medRxiv 2020.08.05.20168435; doi: https://doi.org/10.1101/2020.08.05.20168435
  87. Lurie N, Saville M, Hatchett R, et al. Developing Covid-19 Vaccines at Pandemic Speed. N Engl J Med. 2020;382(21):1969-1973.  [PMID:32227757]
  88. Moderna COVID-19 Vaccine: Moderna COVID-19 Vaccine. FDA Briefing Document. December 17, 2020 [https://www.fda.gov/media/144434/download]
  89. New Brazil data shows disappointing 50.4% efficacy for China’s CoronaVac vaccine. Reuters. January 12, 2021. [https://www.reuters.com/article/us-health-coronavirus-brazil-coronavirus/n...]
  90. Phase 1/2 Study to Describe the Safety and Immunogenicity of a COVID-19 RNA Vaccine Candidate (BNT162b1) in Adults 18 to 55 Years of Age: Interim Report. medRxiv 2020.06.30.20142570; doi: https://doi.org/10.1101/2020.06.30.20142570
  91. Sahin U et al. Concurrent human antibody and TH1 type T-cell responses elicited by a COVID-19 RNA vaccine. medRxiv 2020.07.17.20140533; https://doi.org/10.1101/2020.07.17.20140533]
  92. Shimabukuro TT, Kim SY, Myers TR, et al. Preliminary Findings of mRNA Covid-19 Vaccine Safety in Pregnant Persons. N Engl J Med. 2021.  [PMID:33882218]
  93. Sinopharm, China Bio-Beijing Company’s new coronavirus inactivated vaccine phase III. December 29, 2020. [http://www.bjbpi.com/news_list.asp...]
  94. Sinovac’s coronavirus vaccine candidate approved for emergency use in China. August 28, 2020. [https://www.reuters.com/article/us-health-coronavirus-china-vaccines/sinov...]
Last updated: August 26, 2021